This study will investigate potential "protective effects" against smoking initiation that may account for the decline in smoking prevalence among African-American youth over the past fifteen years. The reasons for this decline may be specific to African-American youth, but could potentially be the basis for interventions to reduce smoking among all youth. No theoretically-based data have been offered to explain these trends and to demarcate what "protective effects" may be operating, nor have the smoking uptake and establishment process among African-American youth been adequately described. We propose to examine theoretical domains of behavioral, physiological,psychosocial and sociocultural factors that bear upon the initiation of smoking, with particular reference to African-American boys and girls. We will focus upon periods of social and cognitive developmental transition in adolescence, since these are often associated with health behavior change. We will demarcate these periods in terms of school transitions -- from elementary to middle, middle to high, and high school senior to post-graduate. A mixed cross-sectional longitudinal design will follow three cohorts of youth during and for two years past these transition points. Assessment will include written questionnaires and physical measures of nicotine dependence, body mass and obesity. Primary dependent variables will include measures of smoking initiation that reflect an adolescent?s risk of becoming a smoker (susceptibility to smoking uptake and Acquisition Stage of Initiation) as well as actual smoking behavior. The movement of adolescents through the susceptibility continuum and the Acquisition Stages of Change model will be examined. Smoking patterns and the development of nicotine dependence will be documented through self- reported smoking status and Fagerstrom Tolerance Scores. Self-reported smoking and nicotine dependence will be validated through saliva cotinine analysis in a subsample. Factors relevant to each phase of smoking behavior and the change process in this population will be determined with multivariate statistical techniques. A pilot study will be conducted during Years 02 and 03 to explore the role of advertising in the initiation of smoking among African-American youth. Findings will be related to susceptibility measures to explore further the role of advertising in tobacco uptake, with future impact on the development of culturally sensitive intervention programs as well as counter advertising campaigns. Study participants will be drawn from school districts in the Houston area, encompassing a range of socioeconomic strata and urban/rural locales. Community advisory boards will facilitate the school district/community and research/academic relationship. Factors that characterize the uptake and continuation of tobacco use (or that protect against it) will be determined. The long-term goal is to develop culturally appropriate intervention programs for African-American youth built around modifiable psychosocial and cultural protective factors well as to identify high-risk youth most in need of such programs.